The basic purpose of sampling is to collect, for further physical testing or laboratory analysis, a manageable mass of material which is representative of the total mass of material from which it was collected. This manageable mass of material is called a "sample". A totally homogeneous material requires the collection of only a single sample in order to determine its characteristics accurately, but a heterogeneous material, such as shredded integrated circuits and electronic components, requires the collection of many small samples, or increments, which, when combined, will represent the total mass, or lot, with an acceptable degree of accuracy. These increments should, therefore, be collected from all parts of the lot. The most commonly used apparatus for sampling heterogeneous material are the diverter type cutters. With these samplers, the material being sampled falls by gravity from the end of an overhead conveyor into a diverter which is moved back and forth across the flow of material. In using this type of equipment, some of the particles being sampled invariably fall on the edges of the diverter and are lost, resulting in a sample which is not a true representation of the total mass of the original lot.